Method for packing articles in an elastic packing material and device to carry out said method

ABSTRACT

The method relates to a method for packing articles and/or objects. Articles are packed in an elastic packing material ( 2 ) and the elastic packing material is stretched during the packing process. To achieve this, the packing material is arranged in a receptacle ( 1 ) in which a partial vacuum is produced. The packing material is stretched due to the pressure that the outside air exerts upon it. The item that is to be packed is then placed in or on the packing material. Once the vacuum has been removed, the packing material automatically reverts back to its original position by virtue of its own elasticity and is applied to the packing items. The invention also relates to a device to carry out such a method.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a method for packaging articles and/or objectsand a device for carrying out said method.

2. Description of the Related Art

According to the prior art, articles or objects of the most differentkinds are packaged with various packaging materials.

According to the prior art, articles or objects, including foods, arepackaged with packaging materials which are formed elastically. Onaccount of the packaging methods belonging to the prior art, the fieldsof application for these packaging methods, in which the articles orobjects are packaged with elastically formed packaging materials, arevery limited.

The packaging methods belonging to the prior art for a packaging of anarticle or object with a elastic packaging material are executed on theone hand with the aid of stretchers.

Hereby an expansion of the elastic packaging material is attained bymeans of the varying running speeds of rollers between which the elasticpackaging material is guided. After the expanding of the packagingmaterial, the article to be packaged is placed on or in the packagingmaterial, and the elastic packaging material contracts through itsrestoring forces.

This method belonging to the prior art has the disadvantage that damageto the packaging material may occur through the expanding of thepackaging material by means of the rollers.

The method belonging to the prior art is moreover very cost-intensive,as the mechanical expansion has to be executed very quickly on the onehand and high forces have to be generated for the expansion on theother.

Moreover, the packaging method belonging to the prior art has thedisadvantage that it is hardly possible to pull the packaging materialin its length and simultaneously in its width by means of thestretchers.

A further disadvantage of this method is that the expansion forces to begenerated pull the elastic packaging material into a smooth, monoplaneshape and thus a simultaneous shaping of the packaging material is notpossible. For example, the packaging material formed as a monoplane foilbecomes larger during expansion. It always remains, however, a monoplanefoil and does not form a shape, for example a sleeve or the like.

A further disadvantage is that the force applied for expanding theelastic packaging material always acts on the packaging material onlylinearly at the contact points between the rollers. With this method,the entire force needed to expand the total surface of the packagingmaterial is applied between two pairs of rollers at one point. This veryoften results in damage.

On the other hand, the prior art includes a packaging method (DE 39 08585 C2) in which, for example, meat is packaged in elastic packagingmaterial. This method belonging to the prior art provides for rods whichare located parallel or approximately parallel or else conically to oneanother in a circle or approximately a circle. On the outside of thecircle formed by the rods, the elastic packaging material is located Inthe form of a sleeve or bag. The meat is pushed through between therods. For the expanding of the packaging material there are now twopossibilities:

Either the packaging material is already placed in pre-expanded state onthe rods, i.e. the packaging material is expanded by mechanical meanswhich act on the rods, or the packaging product must induce an expansionof the elastic packaging material during the pushing through the rods byforcing the rods and the packaging material apart.

When pushing a joint of meat, for example, along the rods, the packagingmaterial is pulled down by the rods. The packaging foil is applied tothe meat with a pressure acting from all sides on the meat.

With this method it is indeed possible for the packaging foil to have ashape (sleeve shape).

However, this method belonging to the prior art has the disadvantagethat the packaging method is not suitable for many products because theexpansion of the rods and of the packaging material has to be induced bythe product. One example to be given in this context is the packaging ofdiapers, as the diapers, due to their deformability, are not in aposition to force the rods and the packaging material apart in a definedway. On being pushed through, the diapers are compressed by theconfronted pressure instead of forcing the rods apart.

If the expanding of the packaging material is to be induced by themechanical means acting on the rods, so that diapers, for instance, canbe packaged, very complex mechanical constructions are necessary forthis purpose.

A further disadvantage of this packaging method belonging to the priorart is that the expansion means used are always inside the packagingduring the packaging procedure and can thus severely impede thepackaging procedure.

SUMMARY-OF THE INVENTION

Moreover, this method belonging to the prior art has the disadvantagethat it can be executed only very slowly.

The technical problem underlying the invention is in specifying a methodfor the packaging of articles and/or objects, including foods, accordingto which the articles and/or objects can be packaged by a simple meansin a elastic packaging material, with which the elastic packagingmaterial is expanded in the packaging procedure, and in which thepackaging material is strained as uniformly as possible and thus onlylittle per area unit during the packaging procedure, in order to preventdamage to the packaging material. Furthermore a method is to bespecified in which the expansion means for the elastic packagingmaterial do not impede the packaging procedure. Moreover, the packagingmaterial is to be expanded uniformly and/or in a defined manner so thatit clings after the packaging under a desired pressure to the commodityto be packaged. A packaging method is to be specified in which theelastic packaging material is expanded in such a way that the elasticpackaging material assumes predefined shapes in order to meet thediffering demands of various articles or objects to be packaged.Moreover, a packaging method is to be specified with which it ispossible to package articles or objects from the most diverse areas.Moreover, a device for carrying out the method is to be specified.

In accordance with the method according to the invention, elasticpackaging material is exposed to an atmospheric differential pressure ina receptacle, A partial vacuum is generated in the receptacle betweenthe packaging material and the receptacle wail. The external airpressure acts on the other side of the packaging material. By this meansthe elastic packaging material is expanded and the commodity to bepackaged is then placed on and/or under or in the expanded packagingmaterial. The partial vacuum is then released. The elastic packagingmaterial is restored, at least to the extent that is clings at leastpartially to the commodity to be packaged.

The elastic packaging material is made, for example, of polyolefinelastomer or polyurethane elastomer and of monoplane configuration. Itis possible to use a single-ply or multi-ply foil. In the case of amulti-ply foil, at least one foil ply can consist of another material.For example, the combination with polyvinyl dichloride (PVDC) orethylene vinyl alcohol (EVOH) is possible in order, for example, toincrease the gas impermeability of the foil.

In the method according to the invention, foils which have a plythickness of between 20 and 200 μm are used with preference. Theexpandability in the elastic area of the foil is advantageously between30% and 400%. With most packagings it is practicable to work with anexpansion of around 50% to 150%.

In accordance with the method according to the invention, the externalair pressure acting on the entire surface of the packaging material actsas an expansion force in that a partial vacuum is generated on theopposite side of the packaging material. Depending on how great thepartial vacuum is, the external air pressure acts as an expansion forcebetween 0 bar and almost 1 bar per cm² of the packaging material.

For example, a pressure of up to approximately 100 kg acts on a 10 cm×10cm large piece of the packaging material, which pressure is sufficientalso to induce the expansion of very strong elastic foils.

Elasticity is taken to mean the independent resumption of the formershape after a change of shape. Elasticity is the characteristic of solidbodies to cancel again their change of shape (deformation) assumed underthe action of external force after cessation of the action of the force(Brockhaus, 18th edition (anniversary edition)).

The method according to the invention has the advantage that the elasticpackaging material is exposed during the expansion procedure to nostrains acting through mechanical devices such as rods, stretchers,rollers or the like, which devices often lead to damage to the elasticpackaging material.

The method according to the invention has moreover the advantage thatthe expansion means do not impede the packaging procedure. As thepackaging material is located in a receptacle in which a partial vacuumis generated and as the packaging material is expanded by the externalair pressure, the commodity to be packaged can be placed on and/or underor in the packaging material in a simple manner. There are, for example,no rods or the like, which are to expand the packaging material, in theway. The external air pressure as an expansion force is indeed present.It does not, however, disturb the packaging procedure.

After the releasing of the partial vacuum, the packaging material clingsto the commodity to be packaged without mechanical expansion meansbetween the packaging material and the commodity to be packaged havingto be removed. The air between the packaging material and the commodityto be packaged is displaced.

Moreover, the packaging material in accordance with the method accordingto the invention is expanded extremely uniformly by the action of theexternal air pressure. In accordance with the method according to theinvention, it is possible to undertake longitudinal and transverseexpansions simultaneously in the packaging material. It is, however,also possible to undertake local overexpansions, for example, as edgeprotection for the commodity to be packaged or as protection for thepackaging material. Furthermore, It is possible to give the elasticpackaging material during the expanding any shapes which are suited tothe commodity to be packaged.

The packaging method according to the invention has moreover theadvantage that it can be used on principle in all packaging areas.

By this means it is now possible to use packaging material universally,which is not possible according to the prior art.

This means that the advantages of the elastic packaging material can beutilized for the first time in other packaging areas than in thepackaging areas belonging to the prior art.

Among the advantages of the elastic packaging material is the advantagethat, after the packaging procedure, the elastic packaging materialclings uniformly and closely to the commodity to be packaged through therestoring forces acting in the packaging material on account of theelasticity.

Moreover, in accordance with the method according to the invention, apackaging material can be used which compresses the product after thepackaging or even during the packaging procedure or exerts a uniformmulti-side or all-side pressure on the packaged commodity, which isadvantageous in the packaging of diapers, hygiene paper, sanitary padsor the like. For example, the volume of diapers can be compressed by upto half in accordance with-the method according to the invention, whichcompression permits substantial savings in logistics.

Moreover, in accordance with the packaging method according to theinvention, the air between the commodity to be packaged and thepackaging material is automatically displaced, which is desired inparticular in the packaging of foods. This replaces the extremelyresource-intensive vacuum packaging methods belonging to the prior artin many packagings.

As each packaging material has in general to be larger during thepackaging procedure than the commodity to be packaged, useless andunsightly material surpluses occur with the packaging materialsbelonging to the prior art. These material surpluses can on the one handbe removed in additional operations by sealing off, cutting off or thelike. These material surpluses can, however, also be concealed byshrinking or pressing against the packaging material. It is alsopossible to let these material surpluses project in an unattractivemanner over the packaging, for example in the case of vacuum packagingsfor meat, which is, however, done only in very few cases. This givesrise according to the prior art to the disadvantage that an additionaloperation is necessary in most cases and that undesired materialcut-offs are moreover present.

The elastic packaging material which is used in accordance with thepackaging method according to the invention does not have thesedisadvantages.

Through the method according to the invention, it is possible that thematerial is elastically expanded during the packaging procedure and thatthe packaging material then clings automatically to the commodity to bepackaged as a result of the restoring forces of the packaging material.In accordance with the method according to the invention, it is possibleto use the elastic packaging material universally for many products.

In doing so, the following is achieved: On expanding, the packagingmaterial becomes thinner in its ply thickness. On restoration of thepackaging material, no material surpluses occur, but the packagingmaterial becomes thicker again in its ply thickness and thus attains theply thickness necessary for the packaging. No material surplusoriginates. By this means a material saving of up to 50% compared withthe prior art is attained.

The stability of a packaging is yielded predominantly by the thicknessof the packaging material after the packaging. The thickness of thepackaging material during the packaging does not ply such a substantialrole.

According to the invention, the method for the packaging of articlesrelates to elastic packaging material in most varied configurations andtypes.

Methods for packaging commodities in packaging materials are describedbelow, which materials are formed as an elastic bag, as an elasticsleeve or as an elastic monoplane foil.

1. Bag

A bag consists, for example, of two monoplane foil pieces, for examplesquares, which are superimposed, and with which three lateral edges arefirmly connected with one another in such a way that the bag has an openend. This bag is placed with its open end contacting the all-round edgeof a receptacle or overlapping the all-round edge of the receptacle insuch a way that a space is formed between the external surfaces of thebag and the internal side of the receptacle, in which space a partialvacuum is generated. Through the external air pressure, the bag isexpanded in the space. The commodity to be packaged is then insertedinto the thus expanded bag. Once the partial vacuum in the space hasbeen released, the bag clings automatically to the packaged article onaccount of the restoring forces present in the bag material.

The bag can be placed with its open end in unexpanded or else inexpanded state contacting the all-round edge of the receptacle oroverlapping same.

The bag is advisedly configured in such a way that it has a largerdiameter in the region of its opening than in the central or end regionof the bag. This has the advantage that the bag can be placed by simplemeans with its open end In slightly expanded state overlapping theall-round edge of the receptacle.

The receptacle is advisedly configured in such a way that it is variablein size. The receptacle can be configured adjustably in the length,width and/or depth. The length of the receptacle can, for example, beadjustable by means of a telescopic configuration of the receptacle. Theinternal space of the receptacle can also be configured variably bymeans of a piston located in the receptacle.

2. Sleeve

If the elastic packaging material is configured as a sleeve with twoopen ends, the sleeve is guided through the receptacle. The one open endof the sleeve is placed, like the bag, contacting the all-round edge ofthe receptacle or overlapping same. The other end of the sleeve isplaced in an infeed device of the receptacle and can be continuouslypulled off a dispenser roll. Advantageously the infeed device for thesleeve is placed in an axially displaceable piston in the receptacle sothat the length of the receptacle and thus the length of the packagingenvelope can be varied by displacing the piston. The piston is fixablein the receptacle so that it is not displaced when the external airpressure acts.

The sleeve portion placed in the receptacle is advisedly drawn tightbefore the sleeve portion is expanded by generation of the atmosphericpartial vacuum and acting of the external air pressure in that thedispenser roll on which the sleeve is located is turned back. This hasthe advantage that the sleeve portion in the receptacle does not clingto the receptacle wall during the expanding in folds or waves or inanother non-uniform manner.

Through generation of a partial vacuum and action of the external airpressure, the sleeve portion located in the receptacle is expanded inthe same way as the bag, and the commodity to be packaged can beinserted into the sleeve. The partial vacuum is then released. Thepackaging material is restored by its elasticity, displacing theair-between the commodity to be packaged and the packaging material. Thesleeve portion clings automatically to the inserted commodity to bepackaged.

A welding device as well as a device for placing a perforation line areadvisedly provided in addition in the piston. Sleeve portions can bedetached from the sleeve at the perforated places.

Depending on the commodity to be packaged, the sleeve portion can beclosed, in particular thermally welded, at one or at both ends.

When the sleeve portion with the packaged commodity is pulled out of thereceptacle, the subsequent sleeve is automatically pulled forward insuch a way that a sleeve portion is once again placed in the receptacleand can be placed with the open end at the all-round edge of thereceptacle.

3. Bag and Sleeve

Advantageously the receptacle has on the outside retaining means for thebag opening or the sleeve opening. The retaining means are advisedlyhook-shaped, and the hooks point away from the receptacle. Once the bagor the sleeve is placed with the opening of the open end on theretaining means, the retaining means are moved pneumatically orhydraulically or electrically in such a way that the bag opening or thesleeve opening lies with tension at the hooks and on and/or at theall-round edge of the opening of the receptacle and thus seals orapproximately seals the space of the receptacle against the externalspace in such a way that a partial vacuum can be generated between thebag or sleeve and the receptacle.

The retaining means can be moved parallel to the surface line of the,for example, cylindrically or cuboidally configured receptacle. It is,however, also possible to move the retaining means radially outwardsaway from the receptacle.

A further retaining possibility for the bag or sleeve consists in thatthe receptacle has a double-wall configuration and a partial vacuum isgenerable in the cavity between the receptacle walls. The receptacle hasin the region of the receptacle opening as a retaining device for theedge of the sleeve opening or bag opening at least one further opening,through which the packaging material is drawn in and retained throughthe partial vacuum generated between the receptacle walls.

The inner receptacle wall determines the geometry of the bag or of thesleeve when a partial vacuum is generated which is so great that the bagor the sleeve clings to the receptacle wall on account of the externalair pressure.

The double-walled embodiment has the further advantage that, on the onehand, the geometry of the external wall of the receptacle can beselected in such a way that it is stable enough to counteract theatmospheric forces occurring on generation of the partial vacuum. Acylindrical shape, for example, has proved to be advantageous.

On the other hand, the double-walled embodiment of the receptacle hasthe advantage that, with a constant geometry of the external wall of thereceptacle, receptacle internal walls deviating from same can beprovided so that various geometries can be preselected for the packagingmaterial. By this means, even exceptionally complex geometries can bepreselected. As the external air pressure acts via the packagingmaterial only on the inside of the inner wall of the receptacle, theforces hereby acting radially outwards are largely eliminated bycounteracting tensile forces in the inner wall of the receptacle. As aresult, plastic, for example, can be used as material for the inner wallof the receptacle instead of heavy steel, so that it is possible at allon the one hand to preselect complex geometries and on the other hand asubstantial cost saving is achieved by this means.

Furthermore, the inner walls of the receptacle can be designedinterchangeably, so that only one packaging device with an outer wall ofthe receptacle is necessary in order to preselect various geometries forthe packaging material by means of the inner wall of the receptacle.

With the double-walled configuration, the inner wall of the receptacleis advisedly configured as a screen. It is, however, also sufficient ifthe inner wall of the receptacle has sufficient openings to guarantee anapproximately uniform pressure in the entire inside space of thereceptacle.

In the case of certain commodities to be packaged, the partial vacuumgenerated in the receptacle is advisedly eliminated in that at least oneopening is provided in the packaging material through the commodity tobe packaged on placement of the commodity to be packaged. Air will flowthrough the opening provided in the packaging material into the space inwhich the partial vacuum was generated, so that the partial vacuum iseliminated. This has the advantage that the partial vacuum has not to beeliminated by the device generating the partial vacuum but that thepartial vacuum is eliminated automatically during the placement of thecommodity to be packaged. By this means, photosensors, for example, canbe renounced, which photosensors would have to signal to a control forelimination of the partial vacuum that the commodity to be packaged isplaced in the packaging material.

4. Monoplane Foil

If the packaging material is configured as monoplane foil, said foil canbe used singly or multiply simultaneously.

4. a) Use of a Single Monoplane Foil

If a monoplane foil is used, it is guided according to the inventionover the all-round edge of a receptacle, whereby the receptacle isadvantageously configured as a trough. The monoplane foil seals thespace of the receptacle against the external space, and a partial vacuumis generated in the receptacle. Through generation of the partialvacuum, the external air pressure acts on the monoplane foil and same isexpanded and pressed into the trough of the receptacle. The commodity tobe packaged can be placed on the expanded monoplane foil. The lateraledges of the monoplane foil are then brought together. The lateral edgesof the monoplane foil are then welded and the atmospheric partial vacuumis released. It is, however, also possible first to release theatmospheric partial vacuum and then to weld the lateral edges.

The lateral edges of the monoplane foil can be thermally welded with oneanother. It is, however, also possible to connect the lateral edges ofthe monoplane foil firmly with one another by other means, for exampleby bonding. In all events, a sleeve is obtained from the monoplane foil.

The sleeve is advantageously separated into sleeve portions. For thispurpose, perforation lines are advisedly provided in the sleeve.

According to need, the ends of the monoplane foil sleeve portion canthen also be closed.

According to this method, it is possible to guide the monoplane foilcontinuously or time-pulsed through the packaging device.

The monoplane foil is advantageously guided by means of conveying means,such as chains, belts or the like.

The conveying means can serve simultaneously as sealing means betweenthe monoplane foil and the all-round edge of the receptacle.

4. b) Use of More Than One Monoplane Foil

If at least two monoplane foils are used, at least two receptacles areadvantageously placed opposite each other. Fundamentally, the expandingprocedure is executed in the same way as the expanding procedure with amonoplane foil. The commodity to be packaged is placed between themonoplane foils. The lateral edges of the monoplane foils are broughttogether and connected firmly with one another.

4. c) Tableau packaging

A tableau is a platen-shape configured material on which the commodityto be packaged is placed. It is possible to guide the commodity to bepackaged, which commodity is placed on the tableau and is to be packagedwith an elastic monoplane foil, through a device which has a receptaclein which the elastic monoplane foil is expanded. The tableau is placedwith the commodity to be packaged in such a way that the expandedmonoplane foil is placed in the receptacle over the commodity to bepackaged. After the release of the partial vacuum, the monoplane foilclings to the commodity to be packaged. Hereby, the lateral edges of themonoplane foil are held mechanically at the edges of the tableau. Thelateral edges of the monoplane foil can now be welded with the tableau.By this means, salmon, for example, can be packaged.

5. General

According to the invention, it is possible to build up a partial vacuumin the receptacle in such a way that the bag, the sleeve or themonoplane foil is expanded as far as the receptacle wall and thegeometry of the packaging material adapts to the receptacle wall. If thepackaging material is configured as a sleeve, for example, said sleevehas a cylindrical shape. If a pipe with a square cross section isselected as a receptacle for this, a shape square in cross section islikewise forced upon the sleeve. In the longitudinal course, however,the packaging material still remains a sleeve.

It is, however, also possible that the packaging material clings onlypartially to the receptacle wall. This has the advantage that, in theevent of the material hardly clinging to the wall, the adhesion forcesare very strongly reduced, as a result of which a continuous forwardmovement of the packaging material in the receptacle is possible. On theother hand, the shape of the packaging material is nonethelessdetermined by the partial clinging to the receptacle wall.

If a sleeve, for example, is again selected as packaging material and asquare cross section pipe as receptacle, the sleeve clings onlypartially in this case to the lateral walls of the square cross-sectionpipe. The sleeve does not reach thereby completely into the corners butspans them radially.

It is, however, also possible according to the invention to select thepartial vacuum in such a way that the packaging material is expandedonly to the extent that a clearance remains between the receptacle walland the packaging material. In this case the geometry of the expandedpackaging material is determined solely by the geometry preselected forthe packaging material.

In this case it is, for example, possible to configure the packagingmaterial as an elastic glove. The elastic glove is expanded by a certainamount in that the atmospheric partial vacuum necessary for theexpanding is built up in the receptacle and the external air pressureacts on the inside surfaces of the elastic glove. This has the advantagethat an elastic glove fitting in unexpanded state close to the skin canbe put on without difficulty, as said glove is larger in expanded statethan the hand. On cancellation of the expansion, the elastic gloveclings automatically to the hand. This is advantageous for use inhospitals or in laboratories in which closely fitting, mostly sterilegloves have frequently to be put on.

With various packagings it is advisable to provide weld seams and/orperforation lines. The weld seams or perforation lines to be provided inthe bag, the sleeve and the monoplane foil sleeve portion areadvantageously curved so that the weld seam adapts in shape to thepackaged commodity.

6. Elastic Restoring Forces

The method according to the invention has the advantage that thecommodity to be packaged can be compressed during the packaging or afterthe packaging procedure by the packaging material on account of therestoring forces acting in the packaging material. This is, for example,advantageous for the packaging of diapers, hygiene paper, sanitary padsor the like, which are allowed to have only a very small spacerequirement for transport, storage and marketing.

A large number of products are configured non-compressibly or hardlycompressibly yet formably. Through the elastic packaging material, aforming of the product, for example of a joint of meat, into a circularor approximately circular cross-sectional shape is achieved.

In the case of products which are neither compressible nor readilyformable, the clinging of the packaging foil and the thus attainedsaving in material is desired, for example, in the case of beverage cansin packs of six.

If no further restoring forces or only limited restoring forces of thepackaging material are to act after the packaging procedure on thecommodity to be packaged, there are three possibilities:

a) On the one hand, the packaging can be adapted to the commodity to bepackaged in such a way that the restoring forces of the packagingmaterial are equal to zero or approximately equal to zero after thepackaging procedure.

b) Furthermore, it is possible to undertake overexpansions of thepackaging material during the expanding of the packaging material, whichoverexpansions are advisedly configured as local overexpansions. By thismeans it is attained that, for example in the area of edges of thecommodity to be packaged, the restoring forces of the elastic packagingmaterial are zero or approximately zero, so that by this means an edgeprotection of the commodity to be packaged is attained. For example,this is desired in the packaging of carton-packaged milk (milk pallets).

c) According to the invention, the packaged commodity can be heated, forexample to 85° C. with the polyolefin elastomer used as packagingmaterial. The heating temperature must in all events remain below themelting point of the packaging material, Through the heating, it isachieved in the case of polyolefin elastomers that the material isstress-relieved.

The following is given as an example of the stress-relieving of thepackaging material:

If the packaging material is expanded, for example, during the packagingprocedure by 100% to 180% and if it contracts to 140% around thecommodity to be packaged, the packaging material without being heatedwould contract again to approximately 100% after the unpacking of thepackaged commodity. If the packaging material is heated, however, thepackaging material will not contract below 140%, The packaging materialis, however, still elastic in the range between 140% and 180%.

This has the advantage that, for example on the unpacking of thepackaged commodity, such as the diapers, the packaging material does notcontinue to contract and possibly make the unpacking more difficult.

If the method according to the Invention is applied to elastic gloves,the gloves normally continue to press on the hands through furtheraction of the restoring forces even after the automatic fitting. If thegloves, however, are made of a corresponding elastic material, forexample, polyolefin elastomer, the gloves can be heated after beingfitted to the hands, so that the material is stress-relieved. Thepackaging material in the form of the gloves, however, remains elastic,i.e. when the user closes his outstretched hand, a new expansion occurson the upper side of the hand, and when he opens his hand, saidexpansion is restored.

Advantageously, the receptacle in which the packaging material isexpanded is adapted in its geometry to the commodity to be packaged.This means that, for example with a circular cross section commodity tobe packaged, the receptacle likewise has a circular cross sectionslightly enlarged compared with the commodity to be packaged.

Advantageously, the geometry of the receptacle can, however, also beshaped deviatingly from the commodity to be packaged. This means that,with a circular cross section commodity to be packaged, the crosssection of the receptacle can, for example, be shaped semicircularly. Inthis case, the base of the receptacle is formed flat, which may beadvantageous when loading the packaging device.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects and features of the present invention will become apparentfrom the following detailed description considered in connection withthe accompanying drawings.

It is to be understood, however, that the drawings are designed as anillustration only and not as a definition of the limits of theinvention. In the drawings, wherein similar reference characters denotesimilar elements throughout the views:

FIG. 1 shows a partial section through the device for the packaging ofan article by means of an elastic bag;

FIG. 2 shows the device according to FIG. 1 with the opening of the bagexpanded:

FIG. 3 shows the device according to FIG. 1 with the bag expanded;

FIG. 4 shows the device according to FIG. 1 with the an article to bepackaged placed in the bag;

FIG. 5 shows the device according to FIG. 1 with a bag placed againstthe article to be packaged;

FIG. 6 shows the top view onto the device according to FIG. 1 in thedirection of the arrow VI;

FIG. 7 shows a modified embodiment of the packaging of an article bymeans of an elastic packaging sleeve;

FIG. 8 shows a section according to line VIII—VIII of FIG. 7;

FIG. 9 shows a detail of the device according to FIG. 7;

FIG. 10 shows a modified embodiment of the packaging of an item by meansof an elastic monoplane foil;

FIG. 11 shows a top view onto FIG. 10 in the direction of the arrow XI;

FIG. 12 shows a perspective view of the device according to FIG. 10;

FIG. 13 shows a section according to line XIII—XIII of FIG. 12;

FIG. 14 shows a section according to line XIV—XIV of FIG. 12;

FIG. 15 shows a modified embodiment;

FIG. 16 shows a device for putting on an elastic glove;

FIG. 17 shows a modified detail of FIG. 1;

FIG. 18 shows a modified detail of FIG. 1;

FIG. 19 shows a modified embodiment;

FIG. 20 shows a section according to line XX—XX of FIG. 19;

FIG. 21 shows a modified embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 shows a receptacle (1) in which a bag (2) consisting of anelastic foil is placed. The bag (2) is suspended on retaining means (4,5) with the edge of its opening (3). The retaining means (4, 5) havehook-shaped ends (6, 7) over which the edge (3 a) of the bag (2) islaid. The edge tension retains the bag (2) with its edge (3 a) on thehooks (6 and 7).

The bag (2) is located in unexpanded state in a space (9) of thereceptacle (1). The receptacle (1) has an opening (10) and at theopposite wall (11) holes (12, 13) as a connection to a device (vacuumpump (109)) generating a partial vacuum.

Between the vacuum pump (109) and the space (9) a valve (106) isprovided. By means of the valve (106), the extraction and intake of theair from the space (9) and into the space (9) are regulated. To extractthe air from the space (9), the valve (106) is switched in such a waythat an opening (107) through which the air can flow in is closed andthe vacuum pump (109) extracts the air from the space (9) via lines(105, 108).

If the space (9) is to be filled with air again after the placing of anarticle into the bag (2), the valve (106) makes a connection between theopening (107) and the line (105) so that air can flow from the externalspace into the space (9). During this procedure a valve (106) blocks offthe line (108) to the vacuum pump (109).

A corresponding device can also be provided behind the hole (13). It is,however, also possible to connect the hole (13) via a line with the line(105).

FIG. 2 shows the bag (2) in the receptacle (1). The retaining means(4,5) have been moved by means of a hydraulically, pneumatically orelectrically operating tensioning device (90) in the direction of thearrow (A) via provided rollers (91) and have spread the retaining means(hooks (6, 7)) on withdrawing in such a way that the edge (3 a) of thebag (2) is expanded in such a way that the edge (3 a) of the bag (2)seals the space (9) of the receptacle (1) against the external air (15)and thus against the external air pressure.

According to FIG. 3, an atmospheric partial vacuum has been generated inthe space (9) through extraction of air from the space (9) by means of adevice (14) (not shown), so that the bag (2) clings to the inner sidesof the walls (11, 16, 17) of the receptacle (1). The bag (2) is now inan expanded state.

According to FIG. 4, an article (19) to be packed can now be guidedthrough the opening (10) of the receptacle (1) and the opening (18) ofthe bag into the receptacle (1) and the bag (2) without mechanical meansbeing in the way during this procedure.

According to FIG. 5, the article (19) is in the bag (2), and the partialvacuum in the space (9) of the receptacle (1) has been released, so thatthe bag (2) has clung automatically on account of its elasticity to theinserted article (19), where applicable under exertion of a pressureonto the article (19). In this procedure the air between the article(19) and the bag (2) is displaced.

Air can flow unimpeded through the opening (10) of the receptacle (1)and the opening (3) of the bag (2) into the front area of the bag (2) inthe space between the inserted article (19) and the edge (3 a) of thebag still retained by the hooks (6, 7). Between the opening (3) of thebag (2) and the packaged article (19), the bag (2) contracts annularlyin the area (19 a).

The tensile forces exerted on the hooks are eliminated (not shown).

The bag (2) is then lifted with its edge (3 a) from the retaining means(4, 5), and the packaged article (19) can be withdrawn from thereceptacle (1) through the opening (10). The retaining means (4, 5) donot disturb this procedure, as they are flexibly mounted in theirattachments points at the tensioning means (90).

As is to be gathered from FIG. 6, the receptacle (1) has fourhook-shaped retaining devices (20 a, 20 b, 20 c, 20 d) which expand theopening (3) of the bag (2) by means of the tensioning means (90) andpull said opening over the edge (8) of the receptacle (1). Thereceptacle (1) has in the present embodiment an approximatelyrectangular cross section in order to be able to package joints of meatreadily airtight with the device.

The retaining devices according to FIGS. 1 through 6 are also to be usedfor a packaging sleeve.

According to FIG. 7, one sleeve portion (26 a) respectively is used froma longer elastic sleeve (26) which is withdrawable according to FIG. 9from a dispenser roll (49).

According to FIG. 7, the elastic sleeve is guided by a piston (24) in areceptacle (23) into the space (36) provided to take the packagingmaterial. The piston (24) has for this purpose an infeed opening (25)for the sleeve portion (26 a). The receptacle (23) is of two-walleddesign in this embodiment, which is, however, not compulsory. Thereceptacle (23) has between the walls (27 and 37) a cavity (28) in whicha partial vacuum is generated via lines (29). The sleeve portion (26 a)can for its part, as shown in FIGS. 1 through 6, be elastically expandedby generation of a partial vacuum in the space (36).

In modification of the embodiment according to FIGS. 1 through 6, thesleeve end (30) is fixed in the opening (31) of the receptacle (23) insuch a way that a partial vacuum is generated in the cavity (28) betweenthe walls (27 and 37) of the receptacle (23). Through openings (32, 33)the front end of the sleeve portion (26 a) is drawn in at the edges (28a) of the double wall in the area of the opening (31) through thegeneration of the partial vacuum In the space (28). A partial vacuum isthen generated via openings (34, 35) in the space (36) enclosed by thedouble walling, so that the sleeve portion (26 a) clings to the innersides (37) of the receptacle (23), as shown in FIG. 3.

Through this embodiment, an article for its part can be introduced intothe expanded elastic sleeve portion (26 c) (broken line).

This device is appropriate especially when liquid or pasty articles inthe interior of the receptacle are to be introduced into the packaging.In the case of liquid or pasty articles it is not necessary for theopening (31) to correspond to the maximum diameter of the article to beintroduced.

The inner walling of the double wall can in a further embodiment of theinvention (not shown) be replaceable.

In this receptacle, the bag (2) is also placeable in the same way as inFIGS. 1 through 6.

The piston (24) is configured displaceably in the direction of the arrow(B), so that variously long sleeve portions (26 a) can be placed in thereceptacle and corresponding articles can be packaged. Thus, receptacle(23) has an adjustable length (L).

FIG. 8 shows the device with the piston (24) of FIG. 7 in thecontinuation of the device to the left. To seal the space (36) with thesleeve outlet (103), in which space a partial vacuum is generated ascompared with the external air (39), a seal (40) is provided between thepiston (24) and the receptacle wall (37). The seal (40) is a hollow sealand can be configured inflatable, so that it can be used on the one handto seal the space (36), but on the other hand also to fix the piston(24) in its respective position.

According to FIG. 9, the sleeve portion (26 a) is advantageously drawnfrom a dispenser roll (49). The packaging sleeve (26) drawn from thedispenser roll (49) is guided in the direction of the arrow (C) into asleeve inlet (41). In order to guarantee an approximately tight seal ofthe sleeve inlet (41) against the external air pressure, a resilientsealing device (42) is provided here.

To expand the sleeve portion (26 a), a partial vacuum is generated forits part in the space (36) in that the air present in the space (36) isextracted in the direction of the arrows (E and F).

After generation of the partial vacuum, the external air pressure actsinside the sleeve portion (26 a) via the opening (31) (FIG. 7) on thesleeve portion (26 a) and expands said sleeve portion as far as theposition (26 c) marked with a broken line, so that the sleeve portionpractically fills out the space (36).

According to FIG. 8, a sleeve portion (26 b) is simultaneouslypre-opened but not expanded in a space (48) upstream from the piston(24) by the air pressure acting from outside.

This has the advantage that the sleeve portion (26 b) can be morereadily opened after removal of the sleeve portion (26 a) from thedevice, as the adhesion forces which act between two foil lengths arecountered by the pre-opening or the adhesion forces are cancelledcompletely. Through the pre-opening, the utilization of release agentssuch as powder and the like is virtually eliminated in the production ofthe packaging sleeve.

In the piston (24) are located a welding rail (43) and a perforationblade (44) which can be moved in the direction of the arrow (D) by meansof a pneumatic cylinder (45) in order to apply a weld seam (47) and aperforation line between the sleeve portion (26 a) and the follow-onsleeve (26) in a zone (46).

It is also possible to deactivate the action of the welding device, sothat only a perforation for tearing off a sleeve portion after thepackaging of the article and for removing the packaged article from thespace (36) is generated in the sleeve passing through.

According to FIG. 8, the piston is configured conically enlarging,starting from the sleeve outlet (103), on its side facing the space(36). It is, however, also possible to provide other configurations ofthe piston (24).

According to FIG. 9, the sleeve (26), as already stated, is placed on adispenser roll (49). Prior to generation of the partial vacuum in thespace (36), the sleeve portion (26 a) is tightened in the space (36) sothat it does not cling in folds and/or in creases to the inner wall ofthe receptacle (23). For this purpose the dispenser roll (49) is turnedback in the direction of the arrow (G) once the sleeve end (30) is fixedat the opening (31) of the receptacle (23). The dispenser roll (49) ismounted on two rollers (50 and 51) which are freely rotatable during thepulling of the sleeve (26) from the roll (49). To tighten the sleeve(26), the roller (50) is turned back in the direction of the arrow (H)so that the dispenser roll (49) is moved back in the direction of thearrow (G) and tightens the sleeve (26). In that the roll (49) is drivenby the roller (50), a uniformly large torque always acts on thedispenser roll (49), irrespective of the diameter of the roll (49),which diameter is independent of the sleeve supply still present on theroll (49).

FIGS. 10, 11 and 12 show a receptacle (52) in trough form, whichreceptacle has openings (53). The openings (53) are in connection with adevice which allows a partial vacuum to be generated in the space (54).

An elastic monoplane foil (58) is guided in the direction of the arrow(K) over a sealing lip (55) located at the edge of the receptacle (52),which foil is withdrawable from a dispenser roll (49 a). The monoplanefoil (58) and the receptacle (52) limit the space (54) in which apartial vacuum is generated.

According to FIG. 10, the monoplane foil (58) clings at least partiallyto the Inner walling (59) of the receptacle (52) on account of thepartial vacuum generated. An article (61) to be packaged can be placedin a depression (60) thereby resulting in the monoplane foil on accountof its elasticity.

The monoplane foil is moved in the direction of the arrow (92) (FIG. 12)by means of transport means. A large number of roller pairs (65,93) canbe provided as transport means according to FIG. 10. The space (54) andits transport means are designed in such a way (FIG. 12) that the edges(56, 57) of the monoplane foil (58) run together in area (M), so thatthey can be welded together there by means of two welding rolls (94) ina welding device (66). A sleeve thus results from the monoplane foil, inwhich sleeve the article (61) is located.

The sleeve is transported with the article (61) through an air lock(96). Once the partial vacuum has been released, the monoplane foilclings to the article (61) to be packaged, as did the sleeve portions orbag according to the preceding embodiments.

FIG. 13 shows the packaged article (61) in the still expanded sleeve(95) formed from the foil (58).

The air lock (96) can consist of overlapping rubber lips (97) (FIG. 14)which are flexibly configured in transport direction of the packagedcommodity.

With this device, successive articles can be packaged.

According to FIG. 15, the device according to the invention has tworeceptacles (71, 72) located opposite each other. With thisconfiguration, two monoplane foils (69, 70), each of which is allocatedto a space (77, 78) of the receptacles (71, 72), can be guided over thereceptacles (71, 72).

In a further embodiment of the invention, the receptacles can beconfigured in such a way as shown in FIG. 15. The receptacles locatedopposite each other have bulges (73, 74 and 75, 76 respectively) intowhich the monoplane foils (69, 70) are drawn on generation of thepartial vacuum.

The monoplane foils (69, 70) can be over expanded in the bulges (73, 74,75, 76), as shown by means of FIG. 15, so that after release of thepartial vacuum the monoplane foils (69, 70) have over expanded areas atwhich their restoring forces are approximately zero. These localoverexpansions are desired if the commodity to be packaged has, forexample, edges at which the edge pressure would be too great afterpackaging with the monoplane foils (69, 70). Through the overexpansionsof the monoplane foils (69, 70) it is achieved that the edge pressurecan be deliberately released and reduced.

An over expansion of the packaging material can be achieved with alldevices according to FIGS. 1 through 12 if the described bulges (73, 74,75, 76) are applied in the same way to the receptacles according toFIGS. 1 through 12.

FIG. 16 shows as a further embodiment a receptacle (79). An elasticglove (81) has been placed in a space (80) of the receptacle (79). Inaccordance with the embodiments according to FIGS. 1 through 6, such apartial vacuum is generated in the space (80) that the glove (81) isexpanded to such an extent that a hand can comfortably be inserted. Aperson's hand can thus be readily inserted Into the glove (81) throughan opening (82) of the receptacle (79) as well as through an opening(83) of the glove (81). Once the partial vacuum has been released, theglove then clings to the hand.

According to FIG. 16, an electrically driven heating coil (104) isprovided in the space (80). By means of this coil (104), the internalspace and thus the elastic glove can be heated so that, withappropriately selected elastic glove material, the material isstress-relieved after fitting of the glove onto the user's hand, i.e.exerts no further sustained pressure on the user's hand.

According to FIG. 17, a receptacle (86) as was shown in FIGS. 1 through8 is represented, which receptacle has no special retaining and openingmeans for the opening of a bag or sleeve. The edge of the bag or sleeveis placed, for example by hand, at the edge of the receptacle (86) underutilization of the elasticity as represented in FIG. 18.

FIG. 17 shows moreover an unexpanded bag (84) in the receptacle (86).The opening (85) of the bag (84) now has, however, a large diameter thanthe bag (84) itself. This has the advantage that, when placing the bag(84) with a taper (84 a) at the all-round edge of the receptacle (86),said bag can be fixed more readily, manageably for housewives too forexample, at the edge of the receptacle (86) without further technicalaids (see FIG. 18).

This type of bag configuration according to FIGS. 17 and 18 can bereadily produced in that bag portions (98) are punched out or cut out ofa foil sleeve (99) (FIGS. 19, 20) along the line (100) and welded orwelded out (hot-wire welding) at the edges, which bag portions areseparated at their respectively broader ends (101).

FIG. 21 shows the device according to FIG. 1, which device is, however,modified here in such a way that, after the filling of the article (19)into the receptacle, the bag (2) is pierced by means of a sharp object(102). With this configuration, the external air penetrates abruptlyinto the space (9), so that a very rapid functional sequence and thus arapid successive packaging of articles becomes possible.

This configuration has, however, also the advantage that, for example ifthe article (19) to be packaged is skewered shashlik, the wooden spitonto which the pieces of meat are pushed can take over the piercing ofthe packaging bag.

Accordingly, while only a few embodiments of the present invention areshown and described, it is obvious that many changes and modificationsmay be made thereunto without departing from the spirit and scope of theinvention.

What is claimed is:
 1. A device to package at least one article with anelastic packaging material, comprising: a receptacle (1, 23, 52, 71, 72)in which a partial vacuum is generated, at least two openings disposedin the receptacle, wherein one opening is for inserting the at least onearticle and a second opening for the infeed of a sleeve (26); saidsecond opening is closed airtight for feeding the sleeve (26); and apiston (24) in which the infeed opening (25) for the sleeve (26) islocated.
 2. The Device according to claim 1, wherein said piston (24) islocated in the receptacle (23).
 3. The Device according to claim 2,wherein said piston (24) is located displaceably in the receptacle (23).4. The Device according to claim 3, wherein said piston (24) is fixablein the receptacle (23).
 5. The Device according to claim 4, the devicesfor welding, cutting and perforating are configured in such a way thatthe weld seams, cut lines and perforation lines have a curvedconfiguration.
 6. The Device according to claim 2, further comprising athermal welding device (43) is located in the piston (24).
 7. The Deviceaccording to claim 2, wherein said piston (24) comprises a device (44)for the application of a perforation line into the sleeve (26).
 8. Adevice to package at least one article with an elastic packagingmaterial, comprising: a receptacle (1, 23, 52, 71, 72) in which apartial vacuum is generated, at least two openings disposed in thereceptacle, wherein one opening is for inserting the at least onearticle and a second opening is disposed in the receptacle, said secondopening for a sleeve (26); said second opening is closed airtight forfeeding the sleeve (26); wherein the feed opening for the sleeve (26) isconfigured areally enlarging in the direction of the space (36) in sucha way that the feed opening has a widened configuration.
 9. The Deviceaccording to claim 8, wherein the magnitude of the widening correspondsapproximately to the magnitude of the slot.
 10. A method for packagingarticles in a packaging device, comprising the steps of: feeding anelastic packaging material into a receptacle as a foil sleeve (26)through an airtight initial opening in the receptacle; feeding a sleeveportion (26 a) having an open end through the receptacle; placing atleast one displaceable mechanical means on the open end of the sleeveportion in the receptacle such that all edges of the receptacle arecontacted and overlapped forming a space (36), said space being airtightfrom an external atmosphere; generating an atmospheric partial vacuum insaid space (36) for expanding the sleeve portion (26 a); inserting atleast one article into the sleeve portion (26 a); restoring the shape ofthe sleeve portion such that it clings to the article; and separatingthe sleeve portion from the fold sleeve (26).
 11. The Method accordingto claim 10, wherein the elastic packaging material clings at leastpartially to the at least one article to be packaged and exerts apressure acting through the elastic restoring forces of the packagingmaterial on the at least one article to be packaged.
 12. The Methodaccording to claim 10, during insertion of the article to be packagedinto the packaging material, the packaging material is provided with atleast one opening in such a way that the partial vacuum is released. 13.The Method according to claim 10, wherein the packaging material (2, 26,58, 69, 70) is closed on at least one side (3).
 14. The Method accordingto claim 10, wherein the sleeve portion (26 a) is tightened in thereceptacle (23) after the placing at the all-round edge of thereceptacle (23).
 15. The Method according to claim 10, wherein the end(30) of the sleeve portion (26 a) placed at the edge of the receptacle(23) is released from the edge of the receptacle (23) after the releaseof the partial vacuum.
 16. The Method according to claim 10,characterized in that the sleeve portion (26 a) is closed at least oneend (30).
 17. The Method according to claim 10, wherein the sleeveportion (26 a) into which the article to be packaged has been insertedis separated from the sleeve (26).
 18. The Method according to claim 10,wherein a perforation is formed between the sleeve portion (26 a) andthe sleeve (26).
 19. The Method according to claim 10, wherein thebeginning of the sleeve portion (26 b) following the sleeve portion (26a) is pre-opened by the external air pressure acting in the sleeveportions (26 a, 26 b).
 20. The Method according to claim 10, wherein thepartial vacuum is generated between the receptacle (1, 23, 52, 71, 72)and the elastic packaging material (2, 26, 58, 69, 70) in such a waythat the packaging material (2, 26, 58, 69, 70) clings at leastpartially to the at least one wall of the receptacle (1, 23, 52, 71,72).
 21. The Method according to claim 10, wherein the partial vacuum isgenerated between the receptacle (1, 23, 52, 71, 72) and the elasticpackaging material (2, 26, 58, 69, 70) in such a way that the elasticpackaging material (2, 26, 58, 69, 70) is expanded to such an extentthat a clearance remains between the at least one receptacle and theelastic packaging material (2, 26, 58, 69, 70).
 22. The method accordingto claim 10, further comprising the step of thermal welding for closingthe ends connecting the lateral edges and ends of the packagingmaterial.
 23. The Method according to claim 10, wherein a weld seamlying transverse to the running direction of the packaging material hasa curved configuration.
 24. The Method according to claim 10, wherein aperforation line is provided for separation of the continuous packagingmaterial (26, 58, 69, 70) is placed transverse to the running directionof the packaging material.
 25. The Method according to claim 24, saidperforation line lying transverse to the running direction of thepackaging material has a curved configuration.
 26. The Method accordingto claim 10, wherein local overexpansions are generated in the packagingmaterial (2, 26, 58, 69, 70).
 27. The Method according to claim 26, saidlocal overexpansions are formed by the geometry (73, 74, 75, 76) of thereceptacle (71, 72).
 28. The Method according to claim 10, the packagingmaterial is heated after the release of the partial vacuum.
 29. Thedevice according to claim 1, wherein the at least one article is a meatproduct.
 30. A method for packaging meat products in a packaging device,comprising the steps of: feeding an elastic packaging material into areceptacle as a foil sleeve (26) through an airtight initial opening inthe receptacle; feeding a sleeve portion (26 a) having an open endthrough the receptacle; placing at least one displaceable mechanicalmeans on the open end of the sleeve portion in the receptacle such thatall edges of the receptacle are contacted and overlapped forming a space(36), said space being airtight from an external atmosphere; generatingan atmospheric partial vacuum in said space (36) for expanding thesleeve portion (26 a); inserting at least one meat product into thesleeve portion (26 a); restoring the shape of the sleeve portion suchthat it clings to the meat product; and separating the sleeve portionfrom the fold sleeve (26).